Source of Funds
Source-of-funds checks ask where the money or crypto used in a particular relationship or transaction came from. They are distinct from source of wealth, which asks how a person's
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Learning objectives
- Distinguish source of funds from source of wealth.
- Build an evidence chain across fiat accounts, exchanges and self-hosted wallets.
- Recognise when transaction history is inconsistent with the stated source.
What the rule or control is
For fiat, evidence might include bank statements, sale contracts, payslips or audited business accounts. For crypto, the chain can include exchange purchase records, wallet transfers, transaction hashes and evidence linking the customer to the originating account.
Blockchain tracing helps show movement but not necessarily lawful economic origin. A wallet can receive tokens from a sale, salary, mining, theft or another person. Documentary and contextual evidence still matters.
The level of evidence should be proportionate to risk. Large, complex or unusual activity may justify enhanced checks. Firms should document why evidence is sufficient rather than accumulating documents without analysis.
Further analysis
A good assessment tests proportionality and plausibility. If the stated source is salary savings, compare the amount and time period with income evidence; if it is business proceeds, examine ownership, accounts and sale contracts; if it is long-held crypto, trace acquisition and intervening custody where reasonably possible. Gaps do not automatically mean illicit funds, but unexplained contradictions should drive further enquiries. The final file should state what was verified, what remains uncertain and why the residual risk was accepted or declined.
Decision framework
| Question | Why it matters |
|---|---|
| Jurisdiction | Rules differ by customer, entity, activity, location and regulator. |
| Legal classification | The same commercial label can cover legally different products or activities. |
| Evidence | Keep primary-source rules, transaction evidence and dated assumptions. |
| Change control | Re-check when legislation, guidance, product design or customer journey changes. |
Worked example and thought exercise
A customer deposits £250,000 equivalent in ETH and says it came from early investment. Explorer data traces the ETH to a wallet funded in 2017, while historical exchange records show purchases from the customer's bank account. The combined evidence is stronger than either the wallet history or bank statement alone.
Thought exercise: Which fact in the example would most change the legal, tax or compliance conclusion if it were different?
Common mistakes and practical workflow
- Confusing source of funds with current wallet balance.
- Assuming on-chain age proves legitimate origin.
- Requesting source-of-wealth evidence when the question is a specific transfer without explaining why.
- Failing to reconcile stated narrative with transaction history.
Practical workflow
- Define the exact activity, asset, customer and jurisdictions.
- Find the current legislation/regulator or tax-authority source rather than relying on a secondary summary.
- Record the rule version/date and the facts used in the analysis.
- Document controls, evidence and any uncertainty or exceptions.
- Escalate to qualified legal, compliance or tax advice where the decision is material.
Primary sources to verify
- Applicable AML legislation and regulator guidance on CDD/EDD.
- FCA AML/CTF materials for UK cryptoasset firms.
- Internal risk-based source-of-funds policy and evidence standards.
These references identify the primary authority or official guidance used for the educational framework. Always verify the live version before relying on a rule.
Knowledge checkpoint
- What is the main legal/compliance distinction in Source of Funds?
- Which facts or jurisdictional assumptions could change the answer?
- Why should primary-source dates be recorded?
- What is one common mistake that could create compliance or tax risk?
FAQs
❓ Is this lesson legal or tax advice?
No. It is educational. Rules depend on jurisdiction, facts and date; professional advice may be appropriate.
❓ Why does the review date matter?
Crypto regulation and tax guidance change quickly, so legal claims should be checked against current primary sources.
❓ Should a vendor or dashboard be treated as an authority?
No. Vendor outputs are evidence inputs; legal and tax conclusions should be grounded in applicable law and regulator or tax-authority guidance.
❓ What should I do when jurisdictions conflict?
Identify every relevant jurisdiction and obtain qualified advice rather than assuming one country's rules control globally.
Summary
Source-of-funds checks ask where the money or crypto used in a particular relationship or transaction came from. They are distinct from source of wealth, which asks how a person's overall wealth was generated. The disciplined approach is to separate labels from legal classification, record jurisdiction and date, preserve evidence, and verify current primary sources before acting.
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